<?php

/*
 * This file is part of SwiftMailer.
 * (c) 2004-2009 Chris Corbyn
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

/**
 * Processes bytes as they pass through a stream and performs filtering.
 *
 * @package Swift
 * @author  Chris Corbyn
 */
interface Swift_StreamFilter
{
	/**
	 * Based on the buffer given, this returns true if more buffering is needed.
	 *
	 * @param mixed $buffer
	 *
	 * @return boolean
	 */
	public function shouldBuffer($buffer);

	/**
	 * Filters $buffer and returns the changes.
	 *
	 * @param mixed $buffer
	 *
	 * @return mixed
	 */
	public function filter($buffer);
}
